In all areas of laboratory testing, the clinical laboratory must ensure proper quality measures are in place to reduce or eliminate carryover between samples, false positive, and false negative results. Some testing techniques are generally assumed to be better than others (e.g., less prone to yielding false positive and false negative results). For example, quantitative, confirmatory testing using liquid chromatography-tandem mass spectrometry is often taken at face value to be more specific than qualitative, antibody-based detection methods, but this is not always true.
The transition from individual vial to 96-well based, high-throughput sample preparation methods is one of many examples of the progress in clinical laboratory testing. Samples can be processed more rapidly and many automated systems have been developed for processing 96-well plates. Nevertheless, small sample volumes and the small form factor of 96-well plates may increase the likelihood of false-positive results for wells in close proximity to significantly elevated wells. For example, an increased likelihood of false-positive results for wells in close proximity to significantly elevated wells at a rate of approximately 4% has been observed in mass-spectrometry analysis of drugs of abuse using a 96-well format. Error rates may be expected to increase as high-throughput assays are transitioned to plates having a greater number of wells (e.g., 384 well plates or even 1536 well plates).